Supplements that contain lots of pieces of genetic material – or nucleotides as they're called – enhance athletes' endurance capacity, according to a human study that the Serbian sports scientist Sergei Ostojic published in Nutrients. Ostojic used an extract of malted barley, but the same nucleotides are also found in ordinary brewer's yeast.

Nucleotides
Nucleotides consist of a nucleobase, a C5 sugar, and phosphate groups. The design of a nucleotide is shown below.

The DNA and RNA in the cells of all living organisms are made up of nucleotides like the ones above. Genetic material is shaped like a spiral staircase, and when two nucleotides are attached to each other they form a step. The cells read the DNA by continuous walking up and down the staircase.

Nucleotides are in our food, and although we can make nucleotides ourselves, there are indications that nucleotide supplementation may yield interesting effects for athletes. If you give nucleotides to rats, for example, their red blood cells start to produce more 2,3-diphosphoglycerate. [J Nutr. 1999 Mar;129(3):662-5.] And as a result the haemoglobin in the red cells releases oxygen more easily to the organs – and nucleotide supplementation probably also improves oxygen transport.

Study
Ostojic gave 15 active male students 50 mg nucleotides every day for two weeks. The nucleotides given were cytidine 5'-monophosphate, uridine 5'-monophosphate, guanosine 5'-mono-phosphate and adenosine 5'-mono-phosphate. Their structural formulae are shown above.

Fifteen other students were given a placebo.

Ostojic extracted his nucleotides from malted barley, but if you consumer 2-3 g brewer's yeast, you'd also consume about 50 mg nucleotides. If you're healthy and don't suffer from gout, this amount shouldn't give you any problems. The human body produces about 750 mg nucleotides daily and breaks down about the same amount.

More endurance capacity

Before and after supplementation the subjects had to run to the point of exhaustion on a treadmill. During the first minute the subjects ran at a speed of 8 km/hour, and every minute the speed increased by another 2 km/hour. The nucleotide supplementation improved the subjects' endurance capacity.

Improved immune system
When the researchers examined white blood cells from the subjects, they noticed that the supplementation had made their Natural Killer Cells significantly more active. That means that the immune system was performing more effectively against pathogens that tried to enter the body.

Conclusion

"Administration of nucleotides formulation for 14 days improved some of the immunological and exercise performance indices, above baseline and placebo level, in healthy male volunteers, with no adverse effects reported", the researchers conclude.

"Evidence confirmed previous animal studies suggesting that sublingual nucleotides may provide some benefits as immunostimulatory and ergogenic agents. Further studies are needed to extend these results, seeking to clarify the mechanism by which improvements occur."